1. Field
This disclosure is generally related to working environment monitoring. More specifically, this disclosure is related to estimating stress factors of a worker using temporal work patterns.
2. Related Art
Management of companies and task designers have been interested in measuring factors contributing to a worker's stress, including workload, autonomy, and productivity perceived by the worker. By acquiring worker-stress related information, a task or process designer can optimize the designed task or system. Such information becomes increasingly important due to the increased role of technology and the use of complex procedures.
Various techniques exist for assessing a worker's stress factors, among which the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) scale test is one of the most widely used tools for workload assessment. The NASA-TLX is a multi-dimensional rating tool that is used to derive an overall workload rating based upon a weighted average of six workload sub-scale ratings. The NASA-TLX uses the following six sub-scales: mental demand, physical demand, temporal demand, effort, performance, and frustration level. Although software packages for NASA-TLX have been developed to automate most of the analysis procedure, there are still several drawbacks for implementing NASA-TLX.
Methods for administering a NASA-TLX scale test include observing the worker, interviewing the worker, and asking the worker to fill out a survey. Such processes can be tedious or cumbersome to the worker, especially if performed repeatedly. In addition, the NASA-TLX can be administered either on-line (while the worker is performing the task) or post-trial (after the task has been performed). When administered on-line, the TLX can be intrusive to task performance, whereas when administered post-trial, the worker may have forgotten high workload aspects of the task. Hence, it is desirable to provide a technique that can be used to estimate task stress on a worker without the aforementioned problems.